Intermitter for gas lift wells



May 21, 1968 H. E. LEGGETT 3,384,105

INTERMITTER FOR GAS LIFT WELLS Filed Dec. 13, 1965 LOW PRESSURE AIR 4 HIGH PRESSURE AIR HAROLD E. LEGGETT INVENTOR.

A T TORNE Y United States Patent 3,384,105 INTERMITTER FOR GAS LIFT WELLS Harold E. Leggett, Dallas, Tex., assignor to Timeco, Inc., Fort Worth, Tex., a corporation of Texas Filed Dec. 13, 1965, Ser. No. 513,514 3 Claims. (Cl. 137-209) ABSTRACT OF THE DISCLOSURE An intermitter for raising liquid in the tubing of a gas lift well and including a balance beam having a container mounted on an arm thereof and a counterweight on the remaining arm and a stationary reservoir above the container. A valve arrangement operated by a low pressure air line causes liquid to flow back and forth between the container and the reservoir at regulated intervals. The resulting tilting of the balance beam opens and closes a valve which introduces high pressure air into the well annulus for rasing liquid in the tubing.

This invention relates to pneumatic intermitters and has reference to time cycle controllers for use with gas lift wells.

In some oil wellsliquid is raised to the earths surface by applying extraneous pneumatic pressure to the annulus between the well casing and the well tubing. There is a gas lift valve or other means of entrance on or in the tubing below the normal static level of oil or other liquid in the well casing. The source of pressure is usually a large capacity air compressor, but pressure may be from another source such as a gas well in the vicinity. Pressure is applied to the annulus intermittently so as to provide periods of time during which oil and perhaps salt water are allowed to accumulate in the lower portion of the well casing. The period of time required for the liquid to reach its maximum level depends on several factors including viscosity of the liquid, the porosity of the producing formation and the natural gas pressure of the Well. Thus, intermitters are desirable for applying pressure to the well for rasing the liquid, and heretofore such devices, generally, were clock operated mechanisms or were hydraulic devices which were not readily adjustable to meet changing requirements of the well.

An object of the invention is to provide an intermitter of simplified construction for gas lift oil wells, and one which is accurate in its operation.

Another object is to provide an intermitter for gas lift oil wells which may be readily and conveniently adjusted to meet changing requirements of the well on which it is installed.

A further object is to provide an intermitter for the described purpose including a stationary liquid reservoir connected with a container on a balance arm and wherein the return of liquid from the container to the reservoir is rapid so as to conserve the supplied pneumatic pressure and increase the efficiency of the well.

These and other objects will become apparent from the following description and the accompanying drawing which is a combined front elevational view of an intermitter according to the invention and a schematic view of the motor valve, the pilot valve and well operated thereby.

In the drawing, the numeral designates a frame on which the components of the intermitter are mounted. The frame 10 shown is a vertical panel, but other suitable frames may :be used. schematically shown there is a motor valve 11 connected with the upper end of a well casing 12 by a pipe 13. In addition to the casing 12, the well includes a tubing string 14, a well head 15 on the upper end of the tubing string above the casing and a 3,384,105 Patented May 21, 1968 "ice flow line 16 connected with the well head, all in the 11 is shown, it is to be understood that a piston type, not shown, may be used instead.

Pivotally mounted on the support 10, by means of a bearing 17, there is a balance beam 18, the arms 19 and 20 of which are off-set so that one is above the other. Opposite the extending length of the lower arm 20 there is a toggle mechanism 21 comprised of a short pointed lever 22 integral with the balance :beam, a pointed lever 23 pivotally mounted on a bearing 24 supported by the frame 10 opposite the first lever, and a toggle spring 25 engaged on the points of two levers. Upper and lower stops 26 on the frame 10 limit the movement of the pivoted lever 23, and stops 27 above and below the first described lever 22 limit the movement of the balance beam 18.

Mounted on the upper beam arm 19 there is a liquid container 28 which is secured in place by a strap 29. On the remaining or lower arm 20 there is a slidably mounted counterweight 30 which is adjustably secured in place by a set screw 31.

Above the liquid container 28 there is a liquid reservoir 32 secured to the frame 10 by a strap 33. The container 28 and the reservoir 32 are shown in the form of bottles on their sides and the tubing connections to be described extend through stoppers, not shown, in the bottle mouths.

Below the lower lbalance arm 20 is a conventional pilot valve 34, the operating stem 35 of which is directed upwardly. Opposite the extending end of the stem 35 and positioned for contact therewith, there is a plunger 36 which is pivotally connected with the balance arm 20 by a clevis 38 and pin 39. A guide 40 on the frame 10 directs the plunger 36. To those versed in the art it will be apparent that the plunger 36 may be operated by the pivoted toggle lever 23.

The inlet 41 of the pilot valve 34 is connected with the inlet end 42 of the motor valve 11 by a line 43 which includes one or more pressure regulators 44. As shown by the legends High Pressure Air and Low Pressure Air, the air pressure is reduced when it reaches the pilot valve 34. An operating line '45 connects the pilot valve 34 with the mot-or valve 11 in the usual manner, and a short line 46 connects with the exhaust of the pilot valve.

A breather line 47 is connected with the reservoir 32 in the manner referred to in the foregoing and which line extends upwardly in the reservoir to avoid the entrance of liquid in the line. The outer end of the line 47 is provided with a breather cap 48. Also extending into but downwardly in the reservoir 32 there is a container connecting liquid line 49 Which extends into and downwardly in the container 28. The line 49 is branched at a and b to provide a bypass line 50, and the lines 49 and 50 have adjustable needle valves 51 and 5-2 between the referred to branches. The first needle valve 51 has a check valve therebeneath arranged to permit gravity flow of liquid from the reservoir 32 to the container 28 and the second needle valve '52 has a check valve 54 arranged to permit return of liquid to the reservoir. By this arrangement of adjustable needles valves 51, 52, and check valves 53, 54, the liquid may be caused to flow slowly at a selected rate into the container 28 and to return rapidly to the reservoir. To those versed in the art it will be apparent that the bypass line 50, first check valve 53, second needle valve 52 and second check valve 54 may be eliminated, but in which case the return of liquid to the reservoir would be relatively slow. s

An air line 55 connects the upper inner area of the container 28 with an air outlet '56 in the pilot valve 34. At least that portion of the liquid line 49 between the lower branch b and the container 28 and a length of the air line 55 between the container and the pilot valve outlet 30 are fiexible as indicated by the loops therein. For example, such lengths may be of rubber tubing.

At the beginning of a cycle the liquid is fully or nearly fully received in the reservoir 32 and the weight of the counterweight 30 holds the stem 35 of the pilot valve 34 in its down or closed position. The adjustment of the first needle valve 51 allows the liquid to flow slowly into the container 28 At this time the air displaced in the container 28 is exhausted through the air line 55, the pilot valve 34 and the short line 45.

As soon as the accumulated weight of liquid in the container 28 overcomes the weight of the counterweight 30 and the spring action of the toggle mechanism, the plunger 36 on the lower balance arm 20 is suddenly raised, allowing the pilot valve stem to pop up. This action applies pressure through the operating line 45 to open the motor valve 11 and at the same time sup-plies air under pressure to the air line 55. Thus, liquid in the container is displaced and returned to the reservoir 32 by Way of the liquid line 49 and bypass line 50. The displacement of the liquid in the container 28 lightens the latter and the weight of the counterweight again closes the .pilot valve 30 and a spring mechanism, not shown, in the motor valve 11 closes the latter. While the motor valve 11 is open, high pressure air passes therethrough into the well, causing the same to flow.

The invention is not limited to the construction herein shown and des ribed, but may he made in various ways within the scope of the appended claims.

What is claimed is:

1. An intermitter for a gas lift well having a valve with a pressure responsive motor actuator, said valve being connected with a source of high pneumatic pressure and a supply and exhaust type pilot valve having an inlet port, an exhaust port and working outlet port means, the inlet port being connected with a source of low pneumatic pressure, means operatively connecting the outlet port means of said pilot valve with the actuator of said motor valve, said pilot valve including a projecting stem for actuation between its sup-ply and exhaust positions and, said intermitter being comprised of a frame, a balance beam mounted on said frame, a closed container mounted on an arm of said balance beam, counterweight means on the opposite arm of said balance beam, means connected with said balance beam operating said stem, a vented reservoir fixedly mounted above said container, a liquid line connecting the bottom of said reservoir with the bottom of said container, and an air line connecting the top of said container with said air outlet port means of said pilot valve, a quantity of liquid contained in the system comprised by said reservoir, container and liquid nne.

2. An intermitter as defined in claim 1 and including an adjustable needle valve in said liquid line.

3. An inte'rmitter as defined in claim 1 and including spring toggle means connected with said balance beam.

References Cited UNITED STATES PATENTS ALAN COHAN, Primary Examiner. 

